Flexible lighting device having unobtrusive conductive layers

ABSTRACT

A flexible lighting element is provided, comprising: a first substrate; first and second conductive elements over the first substrate; a light-emitting element having first and second contacts that are both on a first surface of the light-emitting element, the first and second contacts being electrically connected to the first and second conductive elements, respectively, and the light-emitting element emitting light from a second surface opposite the first surface; a transparent layer located adjacent to the second surface; and a transparent affixing layer located between the first substrate and the transparent layer, wherein the transparent layer and the transparent affixing layer are both sufficiently transparent to visible light that they will not decrease light transmittance below 70%, and the first and second conductive layers are at least partially transparent to visible light, or are 300 μm or smaller in width, or are concealed by a design feature from a viewing direction.

FIELD OF THE INVENTION

The present invention relates generally to a thin, flexible device thatcontains a number of controllable lighting elements on it. Moreparticularly, the present invention relates to a thin, flexible devicecontaining a number of light-emitting diodes that can be controlled tolight up, such that only the light-emitting diodes can be easily seen.

BACKGROUND OF THE INVENTION

Light-emitting diodes (LEDs) can be used to provide low-cost, low-powerlighting in a variety of situations. However, because these designs canbe complex, the resulting device can be relatively thick, limiting theirusefulness in space-sensitive situations.

Furthermore, the desire to keep devices as thin as possible limits thesize of the LEDs that can be used in a lighting device, thereby limitingthe amount of light the lighting device can produce.

In addition, many LED devices are rigid devices, which limit their usein many situations by fixing their size and shape.

Also, for aesthetic reasons, many designers and consumers would like theLEDs alone to be visible in a lighting element, making them appear as ifthey were lights suspended in mid-air. However, the requirement to haveconductive lines to control the operation of the LEDs has not allowedfor such a design.

It would therefore be desirable to provide a thin, low-power, flexiblelighting device that includes one or more relatively large lightingelements, but that can be easily manufactured in which all elementsaside from the lighting elements were either transparent or at leastvery difficult to see with the naked eye.

SUMMARY OF THE INVENTION

A lighting element is provided, comprising: a first substrate; a firstconductive element located on the first substrate; a second conductiveelement located on the first substrate; a light-emitting element havinga first contact and a second contact, the first and second contacts bothbeing on a first surface of the light-emitting element, the firstcontact being electrically connected to the first conductive element,the second contact being electrically connected to the second conductiveelement, and the light-emitting element being configured to emit lightfrom a second surface opposite the first surface with the light having afirst narrow range of wavelengths between 10 nm and 100,000 nm; atransparent layer located adjacent to the second surface of thelight-emitting element; and a transparent affixing layer located betweenthe first substrate and the transparent layer, the affixing layer beingconfigured to affix the transparent layer to the first transparentsubstrate, wherein the transparent layer and the transparent affixinglayer are both sufficiently transparent to visible light such that theywill not decrease light transmittance below 70%, and the first andsecond conductive layers are at least partially transparent to visiblelight.

The lighting element may further comprise: a first transparentconductive layer formed at least partially adjacent to the first contactand at least partially adjacent to the first conductive element, thefirst transparent conductive layer configured to electrically connectthe first contact and the first conductive element, wherein the firsttransparent conductive layer is sufficiently transparent to visiblelight such that it will not decrease light transmittance below 70%.

The lighting element may further comprise: a second transparentconductive layer formed at least partially adjacent to the secondcontact and at least partially adjacent to the second conductiveelement, the second transparent conductive layer configured toelectrically connect the second contact and the second conductiveelement, wherein the second transparent conductive layer is sufficientlytransparent to visible light such that it will not decrease lighttransmittance below 70%.

The light-emitting element may be configured to at least partiallyoverlap at least one of the first and second conductive elements. Thelight-emitting element may be configured such that it does not overlapeither of the first and second conductive elements.

The light-emitting element may be an ultrathin light-emitting element,having a thickness of between 3 mil and 20 mil. The transparent layermay be one of a second substrate and a hardened conformal coating. Thefirst and second conductive elements may each comprise at least one of aconductive polymer strip, a nano-composite strip, a metal nanowire, acopper strip, an aluminum strip, a silver strip, and a strip containingan alloy of copper, aluminum, or silver. The first substrate may besufficiently transparent to visible light such that it will not decreaselight transmittance below 70%. The first and second conductive elementsmay both be buss bars.

A method of forming a lighting element is provided, comprising: forminga first substrate; applying a first conductive element over the firstsubstrate; applying a second conductive element over the firstsubstrate; installing a light-emitting element over the first substratesuch that a first contact of the light-emitting element is electricallyconnected to the first conductive element and such that a second contactof the light-emitting element is electrically connected to the secondconductive element, the first and second contacts both being on a firstsurface of the light-emitting element; forming an affixing layer overthe first substrate; and forming a transparent layer over thelight-emitting element and the affixing layer such that the affixinglayer affixes the transparent layer to the first substrate, wherein thetransparent layer and the transparent affixing layer are bothsufficiently transparent to visible light such that they will notdecrease light transmittance below 70%, the light-emitting element isconfigured to emit light having a first narrow range of wavelengthsbetween 10 nm and 100,000 nm from the second surface; and the first andsecond conductive layers are both at least partially transparent tovisible light.

The method may further comprise: forming a first transparent conductivelayer at least partially adjacent to the first conductive element,wherein in the operation of installing the light-emitting element, thefirst contact is formed to be at least partially adjacent to the firsttransparent conductive layer, the first transparent conductive layer isconfigured to electrically connect the first contact and the firstconductive element, and the first transparent conductive layer issufficiently transparent to visible light such that it will not decreaselight transmittance below 70%.

The light-emitting element may be installed to at least partiallyoverlap the first conductive element.

The method may further comprise: forming a second transparent conductivelayer at least partially adjacent to the second contact, wherein in theoperation of installing the light-emitting element, the second contactis formed to be at least partially adjacent to the second transparentconductive layer, the second transparent conductive layer is configuredto electrically connect the second contact and the second conductiveelement, and the second transparent conductive layer is sufficientlytransparent to visible light such that it will not decrease lighttransmittance below 70%.

The light-emitting element may be installed to at least partiallyoverlap both the first and the second conductive elements. Thelight-emitting element may be installed such that it does not overlapeither of the first and second conductive elements. The light-emittingelement may be an ultrathin light-emitting element, having a thicknessof between 3 mil and 20 mil. The transparent layer may be one of asecond substrate and a hardened conformal coating. The first and secondconductive elements may each comprise at least one of a conductivepolymer strip, a nano-composite strip, a metal nanowire, a copper strip,an aluminum strip, a silver strip, and a strip containing an alloy ofcopper, aluminum, or silver. The first substrate may be sufficientlytransparent to visible light such that it will not decrease lighttransmittance below 70%. The first and second conductive elements mayboth be buss bars.

A lighting element is provided, comprising: a first substrate; a firstconductive element located over the first substrate; a second conductiveelement located over the first substrate; a light-emitting elementhaving a first contact and a second contact, the first and secondcontacts both being on a first surface of the light-emitting element,the first contact being electrically connected to the first conductiveelement, the second contact being electrically connected to the secondconductive element, and the first light-emitting element beingconfigured to emit light having a first narrow range of wavelengthsbetween 10 nm and 100,000 nm from a second surface opposite from thefirst surface; a transparent layer located adjacent to the secondsurface of the light-emitting element; and a transparent affixing layerlocated between the first substrate and the transparent layer, thetransparent affixing layer being configured to affix the transparentlayer to the first substrate, wherein the transparent layer and thetransparent affixing layer are both sufficiently transparent to visiblelight such that they will not decrease light transmittance below 70%,and the first and second conductive layers are 300 μm or smaller inwidth.

The lighting element may further comprise: a first transparentconductive layer formed at least partially adjacent to the first contactand at least partially adjacent to the first conductive element, thefirst transparent conductive layer configured to electrically connectthe first contact and the first conductive element, wherein the firsttransparent conductive layer is sufficiently transparent to visiblelight such that it will not decrease light transmittance below 70%.

The light-emitting element may be configured to at least partiallyoverlap the first conductive element.

The lighting element may further comprise: a second transparentconductive layer formed at least partially adjacent to the secondcontact and at least partially adjacent to the second conductiveelement, the second transparent conductive layer configured toelectrically connect the second contact and the second conductiveelement, wherein the second transparent conductive layer is sufficientlytransparent to visible light such that it will not decrease lighttransmittance below 70%.

The light-emitting element may be configured to at least partiallyoverlap the first and second conductive elements. The light-emittingelement may be configured such that it does not overlap either of thefirst and second conductive elements. The transparent layer may be oneof a second substrate and a hardened conformal coating. The first andsecond conductive elements may each comprise a conductive metal. Thefirst and second conductive elements may each comprise at least one of:thin layers of copper, aluminum, silver, alloys of copper, aluminum, orsilver, and nano-composites containing copper, aluminum, or silver. Thefirst and second conductive elements may both be metal wires.

A method of forming a lighting element is provided, comprising: forminga first substrate; applying a first conductive element over the firstsubstrate; applying a second conductive element over the firstsubstrate; installing a light-emitting element over the first substratesuch that a first contact of the light-emitting element is electricallyconnected to the first conductive element and such that a second contactof the light-emitting element is electrically connected to the secondconductive element, the first and second contacts both being on a firstsurface of the light-emitting element; applying a transparent affixinglayer over the first substrate; and applying a transparent layer overthe light-emitting element and the transparent affixing layer such thatthe transparent affixing layer affixes the transparent layer to thefirst substrate, wherein the transparent layer and the transparentaffixing layer are both sufficiently transparent to visible light suchthat they will not decrease light transmittance below 70%, thelight-emitting element is configured to emit light having a first narrowrange of wavelengths between 10 nm and 100,000 nm from the secondsurface, and the first and second conductive layers are 300 μm orsmaller in width.

The method may further comprise: applying a first transparent conductivelayer at least partially adjacent to the first conductive element,wherein in the operation of installing the light-emitting element, thefirst contact is formed to be at least partially adjacent to the firsttransparent conductive layer, the first transparent conductive layer isconfigured to electrically connect the first contact and the firstconductive element, and the first transparent conductive layer issufficiently transparent to visible light such that it will not decreaselight transmittance below 70%.

The light-emitting element may be installed to at least partiallyoverlap the first conductive element.

The method may further comprise: applying a second transparentconductive layer at least partially adjacent to the second contact,wherein in the operation of installing the light-emitting element, thesecond contact is formed to be at least partially adjacent to the secondtransparent conductive layer, the second transparent conductive layer isconfigured to electrically connect the second contact and the secondconductive element, and the second transparent conductive layer issufficiently transparent to visible light such that it will not decreaselight transmittance below 70%.

The light-emitting element may be installed to at least partiallyoverlap both the first and the second conductive elements. Thelight-emitting element may be installed such that it does not overlapeither of the first and second conductive elements. The light-emittingelement may be an ultrathin light-emitting element, having a thicknessof between 3 mil and 20 mil. The transparent layer may be one of asecond substrate and a hardened conformal coating. The first and secondconductive elements may each comprise at least one of: copper, aluminum,silver, alloys of copper, aluminum, or silver, and nano-compositescontaining copper, aluminum, or silver. The first substrate may besufficiently transparent to visible light such that it will not decreaselight transmittance below 70%. The first and second conductive elementsmay both be metal wires.

A lighting element is provided, comprising: a first substrate; a firstconductive element located on the first substrate; a second conductiveelement located on the first substrate; a light-emitting element havinga first contact and a second contact, the first and second contacts bothbeing on a first surface of the light-emitting element, the firstcontact being electrically connected to the first conductive element,the second contact being electrically connected to the second conductiveelement, and the light-emitting element being configured to emit lighthaving a first narrow range of wavelengths between 10 nm and 100,000 nmfrom a second surface opposite the first surface; a transparent layerlocated adjacent to the second surface of the light-emitting element; atransparent affixing layer located between the first substrate and thetransparent layer, the transparent affixing layer being configured toaffix the transparent layer to the first substrate; and an opaque designfeature formed over at least one of the first conductive element and thesecond conductive element, the opaque design at least partiallyobscuring at least one of the first conductive element and the secondconductive element from above, wherein the transparent layer and thetransparent affixing layer are both sufficiently transparent to visiblelight such that they will not decrease light transmittance below 70%.

The opaque design may fully obscure at least one of the first conductiveelement and the second conductive element from above.

The lighting element may further comprise: a first transparentconductive layer applied at least partially adjacent to the firstcontact and at least partially adjacent to the first conductive element,the first transparent conductive layer configured to electricallyconnect the first contact and the first conductive element, wherein thefirst transparent conductive layer is sufficiently transparent tovisible light such that it will not decrease light transmittance below70%.

The lighting element may further comprise: a second transparentconductive layer formed at least partially adjacent to the secondcontact and at least partially adjacent to the second conductiveelement, the second transparent conductive layer configured toelectrically connect the second contact and the second conductiveelement, wherein the second transparent conductive layer is sufficientlytransparent to visible light such that it will not decrease lighttransmittance below 70%.

The light-emitting element may be configured to at least partiallyoverlap at least one of the first and second conductive elements. Thelight-emitting element may be configured such that it does not overlapeither of the first and second conductive elements. The light-emittingelement may be an ultrathin light-emitting element, having a thicknessof between 3 mil and 20 mil. The transparent layer may be one of asecond substrate and a hardened transparent conformal coating.

The opaque design feature may comprise: a first opaque design elementformed over the first conductive element, the first opaque designelement at least partially obscuring the first conductive element fromabove; and a second opaque design element formed over the secondconductive element, the second opaque design element at least partiallyobscuring the second conductive element from above.

The first and second conductive elements may both be buss bars. Thefirst and second conductive elements may both be at least partiallytransparent to the selected wavelengths of light. The opaque designfeature may be an ornamental decoration, a frame, optical patternscreated by films, or frames of supporting structures.

A method of forming a lighting element is provided, comprising: forminga first substrate; applying a first conductive element on the firstsubstrate; applying a second conductive element on the first substrate;connecting a positive contact of a light-emitting element to the firstconductive element through the first conductive connector, such that thefirst conductive connector electrically connects the first conductiveelement to the positive contact; connecting a negative contact of thelight-emitting element to the second conductive element through thesecond conductive connector, such that the second conductiveelectrically connects the second conductive element to the negativecontact; applying a transparent affixing layer over the first flexiblesubstrate; applying a transparent layer over the light-emitting elementand the transparent affixing layer such that the transparent affixinglayer affixes the transparent layer to the first substrate; and applyingan opaque design feature over at least one of the first conductiveelement and the second conductive element, the opaque design feature atleast partially concealing at least one of the first conductive elementand the second conductive element from above, wherein the transparentlayer and the transparent affixing layer are both sufficientlytransparent to visible light such that they will not decrease lighttransmittance below 70%, the positive and negative contacts are both ona first side of the light-emitting element, and the light-emittingelement is configured to emit light in the selected wavelengths oflight.

The opaque design may be applied to fully obscure at least one of thefirst conductive element and the second conductive element from above.

The method may further comprise: applying a first transparent conductivelayer at least partially adjacent to the first conductive element,wherein in the operation of installing the light-emitting element, thefirst contact is applied to be at least partially adjacent to the firsttransparent conductive layer, the first transparent conductive layer isconfigured to electrically connect the first contact and the firstconductive element, and the first transparent conductive layer issufficiently transparent to visible light such that it will not decreaselight transmittance below 70%.

The light-emitting element may be installed to at least partiallyoverlap the first conductive element.

The method may further comprise: applying a second transparentconductive layer at least partially adjacent to the second contact,wherein in the operation of installing the light-emitting element, thesecond contact is applied to be at least partially adjacent to thesecond transparent conductive layer, the second transparent conductivelayer is configured to electrically connect the second contact and thesecond conductive element, and the second transparent conductive layeris sufficiently transparent to visible light such that it will notdecrease light transmittance below 70%.

The light-emitting element may be installed to at least partiallyoverlap both the first and the second conductive elements. Thelight-emitting element may be installed such that it does not overlapeither of the first and second conductive elements. The light-emittingelement may be an ultrathin light-emitting element, having a thicknessof between 3 mil and 20 mil. The transparent layer may be one of asecond substrate and a hardened conformal coating.

The operation of forming an opaque design feature may comprise: applyinga first opaque design feature over the first conductive element, thefirst opaque design at least partially concealing the first conductiveelement from above; and applying a second opaque design feature over thesecond conductive element, the second opaque design at least partiallyconcealing the second conductive element from above.

The first and second conductive elements may both be buss bars. Theopaque design feature may be an ornamental decoration, a mask, a filter,a frame, optical patterns created by films, or frames of supportingstructures. The first and second conductive elements may be applied onthe outer periphery of the first substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying figures where like reference numerals refer toidentical or functionally similar elements and which together with thedetailed description below are incorporated in and form part of thespecification, serve to further illustrate an exemplary embodiment andto explain various principles and advantages in accordance with thepresent invention. These drawings are not necessarily drawn to scale.

FIG. 1 is an overhead view of a flexible lighting device according to adisclosed embodiment;

FIG. 2 is an overhead cross-sectional view of two lighting elements fromthe flexible lighting device of FIG. 1 according to disclosedembodiments;

FIG. 3 is a circuit diagram showing the electrical connections of alighting structure of FIG. 2 according to disclosed embodiments;

FIG. 4 is a side cross-sectional view of the single lighting element ofFIG. 2 according to disclosed embodiments;

FIG. 5 is a side cross-sectional view of the single lighting structureof FIG. according to disclosed embodiments;

FIG. 6 is an overhead view of a portion of a lighting device havingsemi-transparent conductive elements according to a disclosedembodiment;

FIG. 7 is an overhead view of a portion of a lighting device havingsemi-transparent conductive elements according to another disclosedembodiment;

FIG. 8 is an overhead view of a portion of a lighting device havingsemi-transparent conductive elements according to yet another disclosedembodiment;

FIG. 9A is a side cross-sectional view of the portion of a lightingdevice of FIG. 6 along the line IXA-IXA′ according to a disclosedembodiment;

FIG. 9B is a side cross-sectional view of the portion of a lightingdevice of FIG. 7 along the line IXB-IXB′ according to a disclosedembodiment;

FIG. 9C is a side cross-sectional view of the portion of a lightingdevice of FIG. 8 along the line IXC-IXC′ according to a disclosedembodiment;

FIG. 10A is a side cross-sectional view of the portion of a lightingdevice of FIG. 6 along the line XA-XA′ according to a disclosedembodiment;

FIG. 10B is a side cross-sectional view of the portion of a lightingdevice of FIG. 7 along the line XB-XB′ according to a disclosedembodiment;

FIG. 10C is a side cross-sectional view of the portion of a lightingdevice of FIG. 8 along the line XC-XC′ according to a disclosedembodiment;

FIG. 11 is an overhead view of a portion of a lighting device havingthin wire conductive elements according to a disclosed embodiment;

FIG. 12 is an overhead view of a portion of a lighting device havingthin wire conductive elements according to another disclosed embodiment;

FIG. 13 is an overhead view of a portion of a lighting device havingthin wire conductive elements according to yet another disclosedembodiment;

FIG. 14A is a side cross-sectional view of the portion of a lightingdevice of FIG. 11 along the line XIVA-XIVA′ according to a disclosedembodiment;

FIG. 14B is a side cross-sectional view of the portion of a lightingdevice of FIG. 12 along the line XIVB-XIVB′ according to a disclosedembodiment;

FIG. 14C is a side cross-sectional view of the portion of a lightingdevice of FIG. 13 along the line XIVC-XIVC′ according to a disclosedembodiment;

FIG. 15A is a side cross-sectional view of the portion of a lightingdevice of FIG. 11 along the line XVA-XVA′ according to a disclosedembodiment;

FIG. 15B is a side cross-sectional view of the portion of a lightingdevice of FIG. 12 along the line XVB-XVB′ according to a disclosedembodiment;

FIG. 15C is a side cross-sectional view of the portion of a lightingdevice of FIG. 13 along the line XVC-XVC′ according to a disclosedembodiment;

FIG. 16 is a side cross-sectional view of the flexible lighting deviceof FIG. 7 along the line XIVB-XIVB′ where the conductive elements areobscured by design features according to yet another disclosedembodiment;

FIGS. 17A-17C are side cross-sectional views illustrating amanufacturing process of the flexible lighting device of FIGS. 7 and 8according to disclosed embodiments;

FIG. 18 is a flow chart showing a manufacturing process of a flexiblelighting device according to a disclosed embodiment;

FIGS. 19A and 19B are flow charts showing a process of forming afirst/second electrical connecting structure over a first transparentsubstrate from FIG. 18 according to disclosed embodiments;

FIG. 20 is a flow chart showing a process of forming a light elementover first and second connecting structures from FIG. 18 according to adisclosed embodiment;

FIG. 21 is an overhead view of a portion of a lighting device in whichindividual lighting elements can be selectively activated according toyet another disclosed embodiment.

FIG. 22A is a side cross-sectional view of the flexible lighting deviceof FIG. 21 along the line XVIIA-XVIIA′ according to a disclosedembodiment;

FIG. 22B is a side cross-sectional view of the flexible lighting deviceof FIG. 21 along the line XVIIB-XVIIB′ according to a disclosedembodiment; and

FIG. 22C is a side cross-sectional view of the flexible lighting deviceof FIG. 21 along the line XVIIC-XVIIC′ according to a disclosedembodiment.

DETAILED DESCRIPTION

The instant disclosure is provided to further explain in an enablingfashion the best modes of performing one or more embodiments of thepresent invention. The disclosure is further offered to enhance anunderstanding and appreciation for the inventive principles andadvantages thereof, rather than to limit in any manner the invention.The invention is defined solely by the appended claims including anyamendments made during the pendency of this application and allequivalents of those claims as issued.

It is further understood that the use of relational terms such as firstand second, and the like, if any, are used solely to distinguish onefrom another entity, item, or action without necessarily requiring orimplying any actual such relationship or order between such entities,items or actions. It is noted that some embodiments may include aplurality of processes or steps, which can be performed in any order,unless expressly and necessarily limited to a particular order; i.e.,processes or steps that are not so limited may be performed in anyorder.

Furthermore, elements having the same number represent the same elementacross the various figures, and throughout the disclosure. Theirdescription is not always repeated for each embodiment, but may beinferred from previous descriptions. Elements that have the same numberbut have the addition of a letter designator indicate distinctembodiments of a more generic element.

Flexible Lighting Device Structure

FIG. 1 is an overhead view of a flexible lighting device 100 accordingto a disclosed embodiment. As shown in FIG. 1, the flexible lightingdevice 100 includes a flexible ribbon 110 containing a plurality oflighting elements 120, a positive conductive element 130, and a negativeconductive element 140, a control circuit 150, a cable sheath 160, and acable 170.

The flexible ribbon 110 serves to give structure and protection to theplurality of lighting elements 120 and the positive and negativeconductive elements 130, 140.

The plurality of lighting elements 120 operate to generate light basedon currents received from the control circuit 150 through the positiveand negative conductive elements 130, 140. In the disclosed embodiments,the lighting elements 120 contain light-emitting elements. In someembodiments these lighting-emitting elements could be light-emittingdiodes (LEDs) that emit light of a particular wavelength. In otherembodiments the light-emitting elements could be LEDs with phosphoruscoatings that serve to scatter single-color light generated by the LEDsto make it white light. In still other embodiments the light-emittingelements could be LEDs that include lenses to focus, diffuse, or colorthe light.

The positive conductive element 130 serves as a means for connecting onenode of each of the plurality of lighting elements 120 to a positivevoltage signal from the control circuit 150. Likewise, the negativeconductive element 140 serves as a means for connecting another node ofeach of the plurality of lighting elements 120 to a negative voltagesignal from the control circuit 150. In the embodiment disclosed in FIG.1, the positive and negative conductive elements 130, 140 can be anysuitable structure that serves to electrically connect nodes of theplurality of lighting elements 120 to positive and negative voltagesignals from the control circuit 150. In the alternative, the negativeconductive element 140 may serve as a means for connecting the othernode in each of the plurality of lighting elements 120 to a groundvoltage. Where a negative voltage signal is referred to in thisdisclosure, it can also mean a ground voltage.

In alternate embodiments multiple positive conductive elements 130 andnegative conductive elements 140 could be provided so that differentlighting elements 120 could be connected to different positive andnegative conductive element 130, 140, thus allowing greater control ofthe operation of individual lighting elements 120.

Furthermore, although the positive and negative conductive elements 130,140 are shown in a particular position in FIG. 1, in alternateembodiments they can be placed at various positions on the lightingdevice.

The control circuit 150 provides positive and negative voltage signalsacross the positive and negative conductive elements 130, 140,respectively, in order to control the operation of the plurality oflighting elements 120. When the control circuit 150 supplies propervoltages to the positive and negative conductive elements 130, 140, theplurality of lighting elements 120 will turn on and emit light. When thecontrol circuit 150 stops providing the proper voltages to the positiveand negative conductive elements 130, 140, the plurality of lightingelements 120 will turn off and cease emitting light.

The cable sheath 160 serves to protect the cable 170 from damage, whilethe cable 170 provides power and control signals to the control circuit150.

In operation, the control circuit 150 will either have a set pattern foroperating the plurality of lighting elements 120, or will receivelighting control signals from an external source indicating how itshould operate the plurality of lighting elements 120. Based on the setpattern or the lighting control signals, the control circuit 150 willprovide appropriate voltages to the positive and negative conductiveelements 130, 140 to activate the plurality of lighting elements 120 atdesired times.

FIG. 2 is an overhead cross-sectional window 180 of two lightingelements 120 from the flexible lighting device 100 of FIG. 1 accordingto disclosed embodiments. As shown in FIG. 2, the cross-sectional window180 discloses that the lighting element: 120 are formed in a lightingstructure 210, in which first and second contact elements (not shown)are connected to the positive conductive element 130 and the negativeconductive element 140, respectively.

The lighting structure 210 is configured to emit light, such as light ofa specific wavelength (e.g., ultraviolet light, blue light, green light,infrared light, or any light with a wavelength between 10 nm and 100,000nm) or light in a range of wavelengths (e.g., white light). In someembodiments the lighting elements 120 can include LEDs that emit lightof a particular wavelength; in other embodiments the lighting elements120 can include LEDs that emit light in a particular range ofwavelengths; and in still other embodiments the lighting elements 120can include LEDs that include lenses to focus, diffuse, or color thelight.

In the various disclosed embodiments, the first and second contactelements are provided on the same side of the lighting element 120. As aresult of this, the lighting element 120 can be connected to thepositive and negative conductive elements 130, 140 with a minimum ofconnective circuitry, thereby minimizing the thickness of the lightingstructure 210, and therefore the thickness of the entire flexiblelighting device 100. In one particular embodiment, the lightingstructure 210 contains a flip-chip LED.

FIG. 3 is a circuit diagram showing the electrical connections oflighting structure 210 in the cross-sectional window 180 of FIG. 2according to disclosed embodiments. As shown in FIG. 3, a lightingelement 120 is electrically connected to a positive conductive element130 through a first conductive element 320. Similarly, the lightingelement 120 is electrically connected to a negative conductive element140 through a second conductive element 325.

FIG. 4 is a side cross-sectional view of the lighting element 120 ofFIG. 2 according to a disclosed embodiment. As shown in FIG. 4, thelighting element 120 in this embodiment includes a light-emittingelement 410 having first and second contact elements 420, 425.

The light-emitting element 410 is configured to emit light, such aslight of a specific wavelength (e.g., ultraviolet light, blue light,green light, infrared light, or any light with a wavelength between 10nm and 100,000 nm), or light in a range of wavelengths (e.g., whitelight).

The first and second contact elements 420, 425 provide an external meansfor the light-emitting element 410 to be electrically connected to thepositive and negative conductive element 130, 140. In the disclosedembodiments the first and second contact elements 420, 425 are contactpads. However, in alternate embodiments they could be any suitable meansof electrically connecting the light-emitting element 410 with externalelements. For example, in some alternate embodiments the first andsecond contact elements 420, 425 could be contact pins. When thelight-emitting element 410 is an LED, the first contact element 420 isan anode, and the second contact element 425 is a cathode.

FIG. 5 is a side cross-sectional view of the lighting structure 210 ofFIG. 2 according to a disclosed embodiment. As shown in FIG. 5, thelighting structure 210 in this embodiment includes a light-emittingelement 410 having first and second contact elements 420, 425.Furthermore, the first contact element 420 is connected to a firstconductive connector 520, while the second contact element 425 isconnected to a second conductive connector 525.

The light-emitting element 410 and the first and the second contactelements 420, 425 operate as described above. As a result, thedescription will not be repeated here.

The first and second conductive connectors 520, 525 are configured toelectrically connect the lighting element 120 to the positive andnegative conductive elements 130, 140. In particular, the first contactelement 420 is connected to the positive conductive element 130 throughthe first conductive connector 520. Likewise, the second contact element425 is connected to the negative conductive element 140 through thesecond conductive connector 525.

Because the first and second contact elements 420, 425 are both formedon the same side of the light-emitting element 410, the first and secondconductive connectors 520, 525 can likewise be placed on the same sideof the light-emitting element 410. As a result, a relatively smallconnection distance is required to connect the first and second contactelements fourth 20, 425 to the positive and negative conductive elements130, 140. This allows for a thinner lighting element 120, as compared toa lighting element that employs a light-emitting element with contactelements formed on opposite sides of the light-emitting element.

In various embodiments, the conductive connectors 520, 525 can be:silver epoxy dots, conductive adhesive, metal pads, or other suitablyconductive metal elements.

In an effort to make the ribbon 110 as appealing to the eye as possible,transparent materials are used wherever possible in the lighting device100. At present, however, no truly transparent materials are availablefor the positive and negative conductive elements 130, 140. Therefore,several solutions are disclosed for making the positive and negativeconductive elements 130, 140 as unobtrusive as possible to the nakedeye. These solutions include: (1) using a semi-transparent material forthe positive and negative conductive elements 130, 140; (2) using a thinwire for the positive and negative conductive elements 130, 140; and (3)obscuring the positive and negative conductive elements 130, 140 with adesign feature of the lighting device 100.

Flexible Lighting Device Using Semi-Transparent Conductive Elements

FIG. 6 is an overhead view of a portion of a lighting device 600 havingsemi-transparent conductive elements according to a disclosedembodiment. As shown in FIG. 6, the portion of a lighting device 600includes a plurality of lighting elements 120, a semi-transparentpositive conductive element 130A, and a semi-transparent negativeconductive element 140A.

In this embodiment, the plurality of lighting elements 120 are formeddirectly above at least a portion of each of the semi-transparentpositive conductive elements 130A and the semi-transparent negativeconductive element 140A. As a result, a first contact element (not shownin FIG. 6) can connect directly to the semi-transparent positiveconductive element 130A (e.g., it can connect directly via a firstconductive connector, also not shown in FIG. 6). Similarly, a secondcontact element (not shown in FIG. 6) can connect directly to thesemi-transparent negative conductive element 140A (e.g., it can connectdirectly via a second conductive connector, also not shown in FIG. 6).

FIG. 7 is an overhead view of a portion of a lighting device 700 havingsemi-transparent conductive elements according to another disclosedembodiment. As shown in FIG. 7, the portion of the lighting device 700includes a plurality of lighting elements 120, a first connecting layer730, a second connecting layer 740, a semi-transparent positiveconductive element 130A, and a semi-transparent negative conductiveelement 140A.

In this embodiment, the plurality of lighting elements 120 are notformed directly over the semi-transparent positive and negativeconductive elements 130A, 140A. As a result, this embodiment requires afirst connecting layer 730 to electrically connect first contactelements (not shown in FIG. 7) to the semi-transparent positiveconductive element 130A, and a second connecting layer 740 toelectrically connect second contact elements (not shown in FIG. 7) tothe semi-transparent negative conductive element 140A. In this disclosedembodiment, the first connecting layers 730, 740 may both be transparentconductive oxide (TCO) layers.

FIG. 8 is an overhead view of a portion of a lighting device 800 havingsemi-transparent conductive elements according to yet another disclosedembodiment. As shown in FIG. 8, the portion of the lighting device 800includes a plurality of lighting elements 120, a plurality of firstconnecting layers 830, a plurality of second connecting layers 840, asemi-transparent positive conductive element 130A, and asemi-transparent negative conductive element 140A.

As with the embodiment of FIG. 7, the plurality of lighting elements 120in this embodiment are not applied directly over the semi-transparentpositive and negative conductive elements 130A, 140A. As a result, theplurality of first connecting layers 830 are provided to electricallyconnect first contact elements (not shown in FIG. 8) to thesemi-transparent positive conductive element 130A, and the plurality ofsecond connecting layers 840 are provided to electrically connect secondcontact elements (not shown in FIG. 8) to the semi-transparent negativeconductive element 140A. In this disclosed embodiment, the plurality offirst and second connecting layers 830, 840 may all be transparentconductive oxide (TCO) layers.

In each of FIGS. 6-8, a semi-transparent material is used for thepositive and negative conductive elements 130A, 140A. Although notentirely transparent, such semi-transparent materials can serve toobscure the positive and negative conductive elements 130A, 140A, makingthem difficult to see, particularly from a distance. In variousembodiments, the semitransparent material used for the positive andnegative conductive elements 130A, 140A can include copper, silver,aluminum, alloys of these elements, and other metals.

It should be understood that although the designs in FIGS. 6-8 are allshown as being symmetrical, this is not required. In other words, inalternate embodiments the plurality of lighting elements 120 could beformed directly over one of the semi-transparent conductive elements130A, 140A, but require a connecting layer to connect to the othersemi-transparent conductive element 130A, 140A. Furthermore, the exactdisplacement of the semi-transparent conductive elements 130A, 140A withrespect to the lighting elements 120 can vary.

FIG. 9A is a side cross-sectional view of the portion of a lightingdevice 600 of FIG. 6 along the line IXA-IXA′ according to a disclosedembodiment. As shown in FIG. 9A, the portion of a lighting device 600includes a first transparent substrate 950, semi-transparent positiveand negative conductive elements 130A, 140A, a light-emitting element410, first and second contact elements 420, 425, first and secondconductive connectors 520, 525, a second transparent substrate 955, andan affixing layer 960.

The first transparent substrate 950 serves as a base for the remainderof the lighting device 600. As a reference direction, the firsttransparent substrate 950 can be considered to be a “bottom” substrateupon which the other elements are stacked. However, this is as a pointof reference only. The lighting device 600 has no inherent direction,and can be oriented in any manner, even with the first transparentsubstrate 950 being on the “top” of the structure.

The first transparent substrate 950 can be made of polyethyleneterephthalate (PET), polyethylene napthalate (PEN), polyester, apolymer, an oxide-coated polymer, a flexible plastic, or any suitablematerial that is transparent to visible light. In alternate embodiments,the substrate 950 need not be transparent, and can simply serve as abackdrop for the lighting elements 120. In such an embodiment, it shouldbe referred to as simply a first substrate 950. In embodiments in whichthe entire lighting device 600 is required to be flexible, the firsttransparent substrate 950 should be made of a flexible material.

The semi-transparent positive and negative conductive elements 130A,140A are located on top of the first transparent substrate 950. Each ismade of a semi-transparent conductive material that is connected to thecontrol circuit 150, and is configured to carry a control currentgenerated by the control circuit 150 to the lighting device 600. Invarious embodiments, the semi-transparent positive and negativeconductive elements 130A, 140A can be made of thin layers of metals,conductive polymers, or transparent conductive oxides.

In the embodiments disclosed in FIGS. 6, 9A, and 10A, thesemi-transparent positive and negative conductive elements 130A, 140Aare semi-transparent buss bars used to conduct electricity throughoutthe flexible lighting device 600. These semi-transparent buss bars aremade of a material that is at least partially transparent to visiblelight. For example, the positive and negative conductive elements 130A,140A in these embodiments can be made of thin layers of metals,conductive polymers, or transparent conductive oxides. In alternateembodiments they can be formed from any suitable semi-transparentstructure used to conduct electricity throughout the flexible lightingdevice 600.

FIG. 9B is a side cross-sectional view of the portion of a lightingdevice 700 of FIG. 7 along the line IXB-IXB′ according to a disclosedembodiment. As shown in FIG. 9B, the portion of a lighting device 700includes a first transparent substrate 950, first and second transparentconnecting layers 730, 740, semi-transparent positive and negativeconductive elements 130A, 140A, a light-emitting element 410, first andsecond contact elements 420, 425, first and second conductive connectors520, 525, a second transparent substrate 955, and an affixing layer 960.

As shown in FIG. 9B, the first and second transparent connecting layers730, 740 are applied over the first transparent substrate 950, and thesemi-transparent positive and negative conductive elements 130B, 140Bare formed over the first and second transparent connecting layer 730,740, respectively. The light-emitting element 410 is formed over thefirst and second transparent connecting layers 730, 740 such that afirst contact element 420 connects to the first transparent connectinglayer 730 through the first conductive connector 520, and such that asecond contact element 425 connects to the second transparent connectinglayer 740 through the second conductive connector 525.

The first and second transparent connecting layers 730, 740 can be madeof any suitable transparent conducting material. For example, the firstand second transparent connecting layer 730, 740 may be made of atransparent conducting oxide such as doped and undoped indium oxide, tinoxides and zinc oxides.

FIG. 9C is a side cross-sectional view of the portion of a lightingdevice 800 of FIG. 8 along the line IXC-IXC′ according to a disclosedembodiment. As shown in FIG. 9C, the portion of a lighting device 800includes a first transparent substrate 950, first and second transparentconnecting layers 830, 840, semi-transparent positive and negativeconductive elements 130A, 140A, a light-emitting element 410, first andsecond contact elements 420, 425, first and second conductive connectors520, 525, a second transparent substrate 955, and an affixing layer 960.

FIG. 9C is similar to FIG. 9B, except that the transparent conductinglayers 830, 840 represent an individual conducting layer for thelight-emitting element 410. The transparent conducting layers 830, 840can be made the same or similar material to be first and secondtransparent conductive layers 730, 740 in the embodiment of FIGS. 7, 9B,and 10B.

FIG. 10A is a side cross-sectional view of the portion of a lightingdevice 600 of FIG. 6 along the line XA-XA′ according to a disclosedembodiment. This cross-sectional view shows a point between lightingelements 120. As shown in FIG. 10A, the portion of a lighting device 600includes a first transparent substrate 950, semi-transparent positiveand negative conductive elements 130A, 140A, a second transparentsubstrate 955, and an affixing layer 960.

FIG. 10A is similar to FIG. 9A, save that the light-emitting element 410and its connectors are not present. However, because thesemi-transparent positive and negative conductive elements 130A, 140Aextend the length of the flexible ribbon 110, they are present betweenlighting elements 120.

FIG. 10B is a side cross-sectional view of the portion of a lightingdevice 700 of FIG. 7 along the line XB-XB′ according to a disclosedembodiment. This cross-sectional view shows a point between lightingelements 120. As shown in FIG. 10B, the portion of a lighting device 700includes a first transparent substrate 950, semi-transparent positiveand negative conductive elements 130A, 140A, first and secondtransparent conducting layers 730, 740, a second transparent substrate955, and an affixing layer 960.

FIG. 10B is similar to FIG. 9B, save that the light-emitting element 410and its connectors are not present. However, because thesemi-transparent positive and negative conductive elements 130A, 140Aand the first and second transparent conducting layers 730, 740 extendthe length of the flexible ribbon 110, they are present between lightingelements 120.

FIG. 10C is a side cross-sectional view of the portion of a lightingdevice 800 of FIG. 8 along the line XC-XC′ according to a disclosedembodiment. This cross-sectional view shows a point between lightingelements 120. As shown in FIG. 10C, the portion of a lighting device 800includes a first transparent substrate 950, semi-transparent positiveand negative conductive elements 130A, 140A, a second transparentsubstrate 955, and an affixing layer 960.

FIG. 10C is similar to FIG. 9C, save that the light-emitting element 410and its connectors, as well as the first and second transparentconducting layers 830, 840 are not present. However, because thesemi-transparent positive and negative conductive elements 130A, 140Aextend the length of the flexible ribbon 110, they are present betweenlighting elements 120. Although there is a gap shown between thesemi-transparent positive and negative conductive elements 130A, 140Aand the first flexible substrate 950, the semi-transparent positive andnegative conductive elements 130A, 140A are supported by the pluralityof first and second transparent conducting layers 830, 840, as well asthe affixing layer 960.

If the lighting device 100 must remain flexible, the positive andnegative conductive elements 130A, 140A should also be configured suchthat they can bend without breaking or losing their ability to carry acurrent.

The light-emitting element 410 is configured to generate light based onthe control current carried on the semi-transparent positive andnegative conductive elements 130A, 140A. One exemplary light-emittingelement 410 used in the disclosed embodiments is a light-emitting diode(LED). An LED has an anode (i.e., a positive side) and a cathode (i.e.,a negative side), and operates to generate light of a specificwavelength (from infrared to ultraviolet, i.e., having a wavelength from10 nm to 100,000 nm) when current flows through the LED from the anodeto the cathode.

In alternate embodiments, a phosphor layer may be deposited above thelight-emitting element 410. This may be a separate layer, or combinedwith the second transparent substrate. A phosphor layer operates toscatter light emitted from the top surface of the light-emitting element410. When the light emitted by the light-emitting element 410 is withinthe wavelength spectrum between ultraviolet and blue light (i.e., fromabout 10 nm to 490 nm), a phosphor layer scatters the emitted light suchthat it becomes white light. In this way, when the light-emittingelements 410 is a light-emitting diode (LED) that emits light of asingle wavelength, the resulting lighting element 120 can generate whitelight. For this reason, many manufacturers of LEDs will manufactureblue- or ultraviolet-emitting diodes that include a phosphor layeralready applied to the light-emitting surface of the LED.

In addition, other alternate embodiments can include a lens depositedover the light-emitting element 410. Such a lens could be provided for avariety of purposes. It could operate to focus the light emitted fromthe light-emitting element 410 in order to increase light output byallowing light to be emitted perpendicular to the surface of the secondtransparent substrate 955; it could act to diffuse light emitted fromthe light-emitting element 410 to allow light to be emitted at a largerangle of incidence from the light-emitting element 410; or it could be acolored lens that acts to color the light emitted from thelight-emitting element 410.

Furthermore, alternate embodiments can include one or both of a heatsink and a heat spreading layer attached to the bottom of the firstflexible substrate 950 (i.e., the side opposite the side on which theremainder of elements are located). A heat sink operates to dissipateheat from the lighting elements 120, while a heat spreader operates tospread the heat such that it is not focused on the point just underneaththe lighting elements 120. A heat sink can be a flexible metal layer(e.g., a metal tape), a flexible ceramic thin-film layer, or anyflexible material that dissipates heat sufficiently. A heat spreader canbe a flexible metal layer (e.g., a metal tape), a flexible ceramicthin-film layer, or any flexible material that spreads heatsufficiently.

In addition, although the embodiments disclosed above use a secondtransparent substrate 955, the second transparent substrate can bereplaced in alternate embodiments with a transparent conformal coat thatis deposited over the light emitting element 410 and then hardened.

Flexible Lighting Device Using Thin Wire Conductive Element

FIG. 11 is an overhead view of a portion of a lighting device 1100having a thin wire conductive element according to a disclosedembodiment. As shown in FIG. 11, the portion of a lighting device 1100includes a plurality of lighting elements 120, a thin wire positiveconductive element 130B, and a thin wire negative conductive element140B.

In this embodiment, the plurality of lighting elements 120 are applieddirectly above at least a portion of each of the thin wire positiveconductive elements 130B and the thin wire negative conductive element140B. As a result, a first contact element (not shown in FIG. 11) canconnect directly to the thin wire positive conductive element 130B(i.e., it can connect directly via a first conductive connector, alsonot shown in FIG. 11). Similarly, a second contact element (not shown inFIG. 11) can connect directly to the thin wire negative conductiveelement 140B (i.e., it can connect directly via a second conductiveconnector, also not shown in FIG. 11).

FIG. 12 is an overhead view of a portion of a lighting device 1200having thin wire conductive elements according to another disclosedembodiment. As shown in FIG. 12, the portion of the lighting device 1200includes a plurality of lighting elements 120, a first connecting layer730, a second connecting layer 740, a thin wire positive conductiveelement 130B, and a thin wire negative conductive element 140B.

In this embodiment, the plurality of lighting elements 120 are notapplied directly over the thin wire positive and negative conductiveelements 130B, 140B. As a result, this embodiment requires a firstconnecting layer 730 to connect first contact elements (not shown inFIG. 12) to the thin wire positive conductive element 130B, and a secondconnecting layer 740 to connect second contact elements (not shown inFIG. 12) to the thin wire negative conductive element 140B.

FIG. 13 is an overhead view of a portion of a lighting device 1300having thin wire conductive elements according to yet another disclosedembodiment. As shown in FIG. 13, the portion of the lighting device 1300includes a plurality of lighting elements 120, a plurality of firstconnecting layers 830, a plurality of second connecting layers 840, athin wire positive conductive element 130B, and a thin wire negativeconductive element 140B.

As with the embodiment of FIG. 12, the plurality of lighting elements120 in this embodiment are not applied directly over the thin wirepositive and negative conductive elements 130B, 140B. As a result, theplurality of first connecting layers 830 are provided to connect firstcontact elements (not shown in FIG. 13) to the thin wire positiveconductive element 130B, and the plurality of second connecting layers840 are provided to connect second contact elements (not shown in FIG.13) to the thin wire negative conductive element 140B.

In each of FIGS. 11-13, a thin wire is used for the positive andnegative conductive elements 130B, 140B. Although not transparent, theuse of thin wires can obscure the positive and negative conductiveelements 130B, 140B from the naked eye, making them difficult to see,particularly from a distance.

As with the designs of FIGS. 6-8, it should be understood that althoughthe designs in FIGS. 11-13 are all shown as being symmetrical, this isnot required. In other words, in alternate embodiments the plurality oflighting elements 120 could be applied directly over one of the thinwire conductive elements 130B, 140B, but require a connecting layer toconnect to the other thin wire conductive element 130B, 140B. Likewise,the displacement of the thin wire conductive elements 130 B, 140 B withrespect to the lighting elements 120 may vary.

FIG. 14A is a side cross-sectional view of the portion of a lightingdevice 1100 of FIG. 11 along the line XIVA-XIVA′ according to adisclosed embodiment. As shown in FIG. 14A, the portion of a lightingdevice 1100 includes a first transparent substrate 950, thin wirepositive and negative conductive elements 130B, 140B, a light-emittingelement 410, first and second contact elements 420, 425, first andsecond conductive connectors 520, 525, a second transparent substrate955, and an affixing layer 960.

The first transparent substrate 950 serves as a base for the remainderof the lighting device 1100. As a reference direction, the firstflexible substrate 950 can be considered to be a “bottom” substrate uponwhich the other elements are stacked. However, this is as a point ofreference only. The lighting device 1100 has no inherent direction, andcan be oriented in any manner, even with the first transparent substrate950 being on the “top” of the structure.

The thin wire positive and negative conductive elements 130B, 140B arelocated on top of the first transparent substrate 950. Each is made of athin wire conductive material that is connected to the control circuit150, and is configured to carry a control current generated by thecontrol circuit 150 throughout the lighting device 1100.

FIG. 14B is a side cross-sectional view of the portion of a lightingdevice 1200 of FIG. 12 along the line XIVB-XIVB′ according to adisclosed embodiment. As shown in FIG. 14B, the portion of a lightingdevice 1200 includes a first transparent substrate 950, first and secondtransparent connecting layers 730, 740, thin wire positive and negativeconductive elements 130B, 140B, a light-emitting element 410, first andsecond contact elements 420, 425, first and second conductive connectors520, 525, a second transparent substrate 955, and an affixing layer 960.

The first and second transparent connecting layers 730, 740 are formedover the first transparent substrate 950, and the thin wire positive andnegative conductive elements 130B, 140B are formed over the first andsecond transparent connecting layer 730, 740, respectively. Thelight-emitting element 410 is formed over the first and secondtransparent connecting layers 730, 740 such that a first contact element420 connects to the first transparent connecting layer 730 through thefirst conductive connector 520, and such that a second contact element425 connects to the second transparent connecting layer 740 through thesecond conductive connector 525.

FIG. 14C is a side cross-sectional view of the portion of a lightingdevice 1300 of FIG. 13 along the line XIVC-XIVC′ according to adisclosed embodiment. As shown in FIG. 14C, the portion of a lightingdevice 1300 includes a first transparent substrate 950, first and secondtransparent connecting layers 830, 840, thin wire positive and negativeconductive elements 130B, 140B, a light-emitting element 410, first andsecond contact elements 420, 425, first and second conductive connectors520, 525, a second transparent substrate 955, and an affixing layer 960.

FIG. 14C is similar to FIG. 14B, except that the transparent conductinglayers 830, 840 represent an individual conducting layer for thelight-emitting element 410.

FIG. 15A is a side cross-sectional view of the portion of a lightingdevice 1100 of FIG. 11 along the line XVA-XVA′ according to a disclosedembodiment. This cross-sectional view shows a point between lightingelements 120. As shown in FIG. 15A, the portion of a lighting device1100 includes a first transparent substrate 950, thin wire positive andnegative conductive elements 130B, 140B, a second transparent substrate955, and an affixing layer 960.

FIG. 15A is similar to FIG. 14A, save that the light-emitting element410 and its connectors are not present. However, because the thin wirepositive and negative conductive elements 130B, 140B extend the lengthof the flexible ribbon 110, they are present between lighting elements120.

FIG. 15B is a side cross-sectional view of the portion of a lightingdevice 1200 of FIG. 12 along the line XVB-XVB′ according to a disclosedembodiment. This cross-sectional view shows a point between lightingelements 120. As shown in FIG. 15B, the portion of a lighting device1200 includes a first transparent substrate 950, thin wire positive andnegative conductive elements 130B, 140B, first and second transparentconducting layers 730, 740, a second transparent substrate 955, and anaffixing layer 960.

FIG. 15B is similar to FIG. 14B, save that the light-emitting element410 and its connectors are not present. However, because the thin wirepositive and negative conductive elements 130B, 140B and the first andsecond transparent conducting layers 730, 740 extend the length of theflexible ribbon 110, they are present between lighting elements 120.

FIG. 15C is a side cross-sectional view of the portion of a lightingdevice 1300 of FIG. 13 along the line XVC-XVC′ according to a disclosedembodiment. This cross-sectional view shows a point between lightingelements 120. As shown in FIG. 15C, the portion of a lighting device1300 includes a first transparent substrate 950, thin wire positive andnegative conductive elements 130B, 140B, first and second transparentconducting layers 730, 740, a second transparent substrate 955, and anaffixing layer 960.

FIG. 15C is similar to FIG. 14C, save that the light-emitting element410 and its connectors, as well as the first and second transparentconducting layers 830, 840 are not present. However, because the thinwire positive and negative conductive elements 130B, 140B extend thelength of the flexible ribbon 110, they are present between lightingelements 120. Although there is a gap shown between the thin wirepositive and negative conductive elements 130B, 140B and the firstflexible substrate 950, the thin wire positive and negative conductiveelements 130B, 140B are supported by the plurality of first and secondtransparent conducting layers 830, 840, as well as the affixing layer960.

In the embodiments disclosed in FIGS. 11-15C, the thin wire positive andnegative conductive elements 130B, 140B are conductive wires that are300 μm or smaller in width, used to conduct electricity throughout theflexible lighting device 100. These thin wire conductive elements can bemade of copper, aluminum, silver, alloys of copper, aluminum, or silver,and nano-composites containing copper, aluminum, or silver, or anysuitable conductive material.

If the lighting device 100 must remain flexible, the first and secondconductive elements 130, 140 should also be configured such that theycan bend without breaking or losing their ability to carry a current.

The light-emitting element 410 is configured to generate light based onthe control current carried on the thin wire first and second conductiveelements 130B, 140B. One exemplary light-emitting element 410 used inthe disclosed embodiments is a light-emitting diode (LED). An LED has ananode (i.e., a positive side) and a cathode (i.e., a negative side), andoperates to generate light of a specific wavelength (from infrared toultraviolet, i.e., having a wavelength from 10 nm to 100,000 nm) whencurrent flows through the LED from the anode to the cathode.

As with the embodiments disclosed above using a semi-transparentconductive element 130A, 140A, embodiments using a thin wire conductiveelement 130B, 140B can deposit a phosphor layer above the light emittingelement 410, can deposit a lens above the light emitting element 410,can include one or both of a heat sink and a heat spreading layerattached to the bottom of the first transparent substrate 950, and canreplace the second transparent substrate 955 with a transparentconformal coat.

Flexible Lighting Device—Concealed Buss Bar

FIG. 16 is a side cross-sectional view of the flexible lighting device1600 similar to that of FIG. 7 along the line IXB-IXB′, in which theconductive elements are concealed by design features according to yetanother disclosed embodiment. As shown in FIG. 16, the portion of alighting device 1600 includes a first transparent substrate 950,positive and negative conductive elements 130C, 140C, a light-emittingelement 410, first and second contact elements 420, 425, first andsecond conductive connectors 520, 525, a second transparent substrate955, an affixing layer 960, and first and second design elements 1670,1675.

The first transparent substrate 950 serves as a base for the remainderof the lighting device 1600. As a reference direction, the firstflexible substrate 950 can be considered to be a “bottom” substrate uponwhich the other elements are stacked. However, this is as a point ofreference only. The lighting device 1600 has no inherent direction, andcan be oriented in any manner, even with the first transparent substrate950 being on the “top” of the structure.

The positive and negative conductive elements 130C, 140C are located ontop of the first transparent substrate 950. Each is made of a conductivematerial that is connected to the control circuit 150, and is configuredto carry a control current generated by the control circuit 150throughout the lighting device 1600. In various embodiments, thepositive and negative conductive elements 130C, 140C can be made ofmetal layers such as silver, aluminum or copper. There is no requirementin this embodiment for the positive and negative conductive elements130C, 140C to either be made of a semi-transparent material or to bemade of a thin wire, since the positive and negative conductive elements130C, 140C will be obscured by the first and second design elements1670, 1675.

The first design element 1670 is formed over exposed portions of thepositive conductive element 130C, and serves to partly or completelyconceal the positive conductive element 130C from view in a selectedviewing direction. It has a width B that is at least as wide as thewidth of the exposed portions of the positive conductive element 130C,and a length at least as long as the length of the exposed portions ofthe positive conductive element 130C. Similarly, the second designelement 1675 is applied over exposed portions of the negative conductiveelement 140C, and serves to part or completely conceal the negativeconductive element 140C from view in the selected viewing direction. Ithas a width A that is at least as wide as the width of the exposedportions of the negative conductive element 140C, and a length at leastas long as the length of the exposed portions of the negative conductiveelement 140C.

In various embodiments, the first and second design elements 1670, 1675can be any decorative or functional feature that can serve to obscurethe positive and negative conductive elements 130C, 140C. For example,they could be a frame for the lighting device 100, decorative stripesrunning the length of the lighting device, optical patterns created byfilms, frames of supporting structures, etc.

As with the embodiments disclosed above using semi-transparentconductive elements 130A, 140A, or thin wire conductive elements 130B,140B, alternate embodiments using an obscured conductive element 130C,140C can deposit a phosphor layer above the light emitting element 410,can deposit a lens above the light emitting element 410, can include oneor both of a heat sink and a heat spreading layer attached to the bottomof the first transparent substrate 950, and can replace the secondtransparent substrate 955 with a transparent conformal coat.

Although FIG. 16 shows an embodiment in which the obscured positive andnegative conductive elements 130C, 140C are set away from thelight-emitting element 410, alternate embodiments can alter the positionof either or both of the obscured positive and negative conductiveelements 130C, 140C (e.g., as seen in FIGS. 6, 9A, and 10A). In someembodiments, a portion of the positive and negative conductive elements130C, 140C may be obscured by the light-emitting elements 410. In such acase, there is no need for a design element 1670, 1675 to obscure thoseportions of the positive and negative conductive elements 130C, 140C. Infact, the design elements 1670, 1675 should avoid covering thelight-emitting elements 410, to avoid interfering with the light emittedfrom these elements.

Method of Manufacturing a Flexible Lighting Device

FIGS. 17A-17C are side cross-sectional views illustrating amanufacturing process of the flexible lighting device 700 of FIG. 7according to disclosed embodiments. FIG. 18 is a flow chart showing amanufacturing process 1800 of a flexible lighting device according todisclosed embodiments.

As shown in FIGS. 17A and 18, the manufacturing process 1800 begins byproviding a first transparent substrate 950 (1810).

As shown in FIGS. 17A, 17B, and 18, a first electrical connectingstructure is then applied over the first transparent substrate (1820),and a second electrical connecting structure is then applied over thefirst transparent substrate (1830).

In the embodiment shown in FIGS. 17A-17C, the first electricalconnecting structure includes a first transparent conducting layer 730applied over the first transparent substrate 950, and a positiveconductive element 130 applied over the first transparent conductinglayer 730. Similarly, in this embodiment, the second electricalconnecting structure includes a second transparent conducting layer 740applied over the first transparent substrate 950, and a negativeconductive element 140 applied over the second transparent conductinglayer 740. However, alternate embodiments can employ different first andsecond electrical connecting structures. For example, in someembodiments the first and second electrical connecting structures can beformed from only the positive and negative conductive elements 130, 140,respectively.

As shown in FIGS. 17C and 18, the manufacturing process 1800 continuesas the lighting element 120 is applied over the first and secondelectrical connecting structures, such that it is electrically connectedto both the first and the second electrical connecting structures(1840).

In the embodiment disclosed in FIG. 17C, a light-emitting element 410 isbrought into contact with the first and second connecting conductors520, 525, which then contact the first and second transparent conductinglayers 730, 740, respectively. In particular, the first and secondconnecting elements 420, 425 on the light-emitting element 410 come intocontact with the first and second conducting connectors 520, 525,respectively. Typically this operation involves a baking step after thelight-emitting element 410 is applied, to dry the connection (i.e., thefirst and second conducting connectors 520, 525.)

In this way the light-emitting element 410 is attached to the first andsecond electrical connecting structures, which can provide controlsignals to the light-emitting element 410. In the embodiment disclosedin FIG. 17C, a first connecting element 420 of the light-emittingelement 410 is connected to the first electrical connecting structure,which serves as a positive control line. Likewise, a second connectingelement 425 of the light-emitting element 410 is connected to the secondelectrical connecting structure, which serves as a negative controlline.

As shown in FIGS. 9B and 18, the manufacturing process 1800 continues asa transparent affixing material 960 is formed over the entire structure(1850).

As shown in FIGS. 9B and 18, the manufacturing process 1800 continues asa second transparent substrate 955 is applied over the entire structure(1860). In such an operation, the first and second transparentsubstrates 950, 955 are pressed together to fix them to each other viathe transparent affixing material 960. During this process, thetransparent affixing material 960 will flow around the light-emittingelements 410 and the first and second electrical connecting structuressuch that it does not disturb these elements, but also affixes them inplace. In the embodiments disclosed in FIGS. 9A-16, little to none ofthe transparent affixing material 960 remains between the light-emittingelements 410 and the second transparent substrate 955. However, inalternate embodiments, some portion of the transparent affixing material960 may remain between the light-emitting elements 410 and the secondtransparent substrate 955.

In one particular embodiment, the transparent affixing material 960 canbe initially affixed to one side of the second transparent substrate955, and then the two pressed down on the rest of the structure. This isby way of example only. In alternate embodiments, the transparentaffixing material 960 could initially be applied first to the firsttransparent substrate 950, the first and second electrical connectingstructures, and the light-emitting elements 410. Alternatively, both thefirst and second transparent substrates 950, 955 can be combined withthe transparent affixing material 960 simultaneously.

FIGS. 19A and 19B are flow charts showing a process of forming afirst/second electrical connecting structure over a first transparentsubstrate from FIG. 18 according to disclosed embodiments.

As shown in FIG. 19A, the process of forming a first/second electricalconnecting structure (1820, 1830) may be as simple as forming aconductive element 130, 140 over the transparent substrate 950 (1910).

In this case, the electrical connecting structure is formed from theconductive element 130, 140 alone. In particular, the first electricalconnecting structure is formed from the positive conductive element 130,while the second electrical connecting structure is formed from thenegative conductive element 140. An exemplary resultant structure can beseen in FIGS. 6 and 9A.

As shown in FIG. 19B, the process of forming a first/second electricalconnecting structure (1820, 1830) may also include forming a transparentconducting layer 730, 740 over the first transparent substrate 950(1920) and forming a conductive element 130, 140 over the transparentconducting layer 730, 740 (1930).

In this case, the electrical connecting structure is formed from thetransparent conducting layer 730, 740 and the conductive element 130,140. In particular, the first electrical connecting structure is formedfrom the first transparent conducting layer 730 and the positiveconductive element 130, while the second electrical connecting structureis formed from the second transparent conducting layer 730 and thenegative conductive element 140. Exemplary resultant structures can beseen in FIGS. 7, 8, 9B, and 9C.

FIG. 20 is a flow chart showing a process of forming a light elementover first and second connecting structures (1840) from FIG. 18according to a disclosed embodiment.

As shown in FIG. 20, this process can include applying a firstconductive material 520 on a first electrical conducting structure(2010), applying a second conductive material 525 on a second electricalconnecting structure (2020), and placing a light-emitting element 410 onthe first and second conductive materials 520, 525 such that a firstelectrode on the light-emitting element connects to the first conductivematerial 520, and a second electrode on the light-emitting elementconnects to the second conductive material 525 (2030).

As shown above, the first and second electrical conducting structurescan be varied in form, but may include simply a conductive element 130,140, or may include a transparent conducting layer 730, 740, with acorresponding conductive element 130, 140 placed on top of theconducting layer 730, 740.

The first and second conductive materials may be formed from: silverepoxy dots, a conductive adhesive, metal pads, or any other suitableconductive material.

Although the drawings with respect to the above manufacturing processshow the conductive elements 130, 140 as being conductive layers, suchas a semi-transparent or opaque buss bar (130A, 140A, or 130C, 140C),the described process is equally applicable to embodiments in which theconductive elements 130, 140 are conductive thin wires (130B, 140B).

Although FIGS. 17B, 18, 19A, and 19B disclose that the positive andnegative conductive elements 130, 140 are deposited in separate steps,in some embodiments they can be formed onto the first transparentsubstrate 950 or the first and second transparent conducting layers 730,740 at the same time.

Although FIGS. 17B, 18, and 20 disclose that the first and secondconductive connectors 520, 525 are applied in separate steps, in someembodiments they can be applied onto the positive and negativeconductive elements 130, 140 at the same time.

Furthermore, although FIGS. 17A-20 disclose layers applied only on topof the first transparent substrate 950, in alternate embodiments one orboth of a heat spreader or a heat sink may be attached to a bottom ofthe first transparent substrate 950.

In addition, in alternate embodiments a phosphor layer and/or a lens canbe deposited above the light-emitting element 410. The secondtransparent substrate 955 may also be replaced with a transparentconformal coat, which is deposited in a viscous state and laterhardened.

Individually-Controlled Light-Emitting Elements

FIG. 21 is an overhead view of a portion of a lighting device 2100 inwhich individual lighting elements 120 can be selectively activatedaccording to yet another disclosed embodiment. As shown in FIG. 21, thelighting device 2100 includes a plurality of lighting elements120A-120F, a plurality of first transparent conductive layers2130A-2130F, and a plurality of second transparent conductive layers2140A-2140F.

The plurality of lighting elements 120A-120F can be any suitablelight-emitting element 410, including the first and second connectionelectrodes (not shown in FIG. 21) located on the same side of thelight-emitting element 410.

The plurality of positive transparent conductive layers 2130A-2130F areisolated from each other, and are configured to connect to the firstconnection electrodes in each of the plurality of lighting elements120A-120F, respectively.

The plurality of negative transparent conductive layers 2140A-2140F areisolated from each other, and are configured to connect to the secondconnection electrodes in each of the plurality of lighting elements120A-120F, respectively.

In this way, signals sent along corresponding pairs of positive andnegative transparent conductive layers (2130A and 2140A, 2130B and2140B, etc.) can be used to individually control each of the pluralityof lighting elements 120A-120F.

FIG. 22A is a side cross-sectional view of the flexible lighting deviceof FIG. 21 along the line XVIIA-XVIIA′ according to a disclosedembodiment. This cross-sectional view is at a first lighting element120A.

As shown in FIG. 22A, a first positive transparent conductive layer2130A and a first negative transparent conductive layer 2140A are formedover a first transparent substrate 950. A first conductive connector520A is formed over the first positive transparent conductive layer2130A, while a second conductive connector 525A is formed over the firstnegative transparent conductive layer 2140A.

A first light-emitting element 410A is placed on the first and secondconductive connectors 520A, 525A such that a first connecting electrode420A of the first light-emitting element 410A is connected to the firstconductive connector 520A, and a second connecting electrode 425A of thefirst light-emitting element 410A is connected to the second conductiveconnector 525A. In this way the first connecting electrode 420A iselectrically connected to the first positive transparent conductivelayer 2130A, and the second connecting electrode 425A is electricallyconnected to the first negative transparent conductive layer 2140A.

Because this is the first light-emitting element 410A, the firstpositive and negative transparent conductive layers 2130A, 2140A extendto a width sufficient to allow room for all subsequent transparentconductive layers (i.e., positive transparent conductive layers2130B-2130F and negative transparent conductive layers 2140B-2140F) tobe formed in a manner such that each are isolated from the firstpositive and negative transparent conductive layers 2140A, 2140A, andfrom one another.

FIG. 22B is a side cross-sectional view of the flexible lighting deviceof FIG. 21 along the line XVIIB-XVIIB′ according to a disclosedembodiment. This cross-sectional view is at a third lighting element120C.

As shown in FIG. 22B, a third positive transparent conductive layer2130C and a third negative transparent conductive layer 2140C areapplied over a first transparent substrate 950. A first conductiveconnector 520C is applied over the third positive transparent conductivelayer 2130C, while a second conductive connector 525C is applied overthe third negative transparent conductive layer 2140C. In addition,first and second positive transparent conductive layers 2130A, 2130B runalongside the third positive transparent conductive layer 2130C in sucha way as to be isolated from the third positive transparent conductivelayer 2130C and from each other. Likewise, first and second negativetransparent conductive layers 2140A, 2140B run alongside the thirdnegative transparent conductive layer 2140C in such a way as to beisolated from the third negative transparent conductive layer 2140C andfrom each other.

A third light-emitting element 410C is placed on the first and secondconductive connectors 520C, 525C such that a first connecting electrode420C of the third light-emitting element 410C is connected to the firstconductive connector 520C, and a second connecting electrode 425C of thethird light-emitting element 410C is connected to the second conductiveconnector 525C. In this way the first connecting electrode 420C iselectrically connected to the third positive transparent conductivelayer 2130C, and the second connecting electrode 425C is electricallyconnected to the third negative transparent conductive layer 2140C.

Because this is the third light-emitting element 410C, the thirdpositive and negative transparent conductive layers 2130C, 2140C extendto a width sufficient to allow room for all subsequent transparentconductive layers (i.e., positive transparent conductive layers2130D-2130F and negative transparent conductive layers 2140D-2140F) tobe formed in a manner such that each are isolated from the thirdpositive and negative transparent conductive layers 2130D, 2140D, andfrom one another.

FIG. 22C is a side cross-sectional view of the flexible lighting deviceof FIG. 21 along the line XVIIC-XVIIC′ according to a disclosedembodiment. This cross-sectional view is at a sixth lighting element120F.

As shown in FIG. 22C, a sixth positive transparent conductive layer2130F and a sixth negative transparent conductive layer 2140F areapplied over a first transparent substrate 950. A first conductiveconnector 520F is applied over the sixth positive transparent conductivelayer 2130F, while a second conductive connector 525F is applied overthe sixth negative transparent conductive layer 2140F. In addition,first through fifth positive transparent conductive layers 2130A-2130Erun alongside the sixth positive transparent conductive layer 2130F insuch a way as to be isolated from the sixth positive transparentconductive layer 2130F and from each other. Likewise, first throughfifth negative transparent conductive layers 2140A-2140E run alongsidethe sixth negative transparent conductive layer 2140F in such a way asto be isolated from the sixth negative transparent conductive layer2140F and from each other.

A sixth light-emitting element 410F is placed on the first and secondconductive connectors 520F, 525F such that a first connecting electrode420F of the sixth light-emitting element 410F is connected to the firstconductive connector 520F, and a second connecting electrode 425F of thesixth light-emitting element 410F is connected to the second conductiveconnector 525F. In this way the first connecting electrode 420F iselectrically connected to the sixth positive transparent conductivelayer 2130F, and the second connecting electrode 425F is electricallyconnected to the sixth negative transparent conductive layer 2140F.

Because this is the sixth (and last) light-emitting element 410F, thesixth positive and negative transparent conductive layers 2130F, 2140Fdo not need to extend beyond a minimum amount required to provide awidth sufficient to allow the sixth positive and negative transparentconductive layers 2130F, 2140F to clear the sixth light-emitting element410.

In the embodiment disclosed in FIGS. 22-23C, the positive and negativetransparent conductive layers 2130A-2130F, 2140A-2140F may be made of amaterial such as metals, transparent conductive inks, or transparentconductive polymers.

In these embodiments, the light-emitting elements 410 are configured togenerate light based on the control currents carried on the relevantpair of positive and negative transparent conducting layers 2130, 2140.One exemplary light-emitting element 410 used in the disclosedembodiments is a light-emitting diode (LED). An LED has an anode (i.e.,a positive side) and a cathode (i.e., a negative side), and operates togenerate light of a specific wavelength (from ultraviolet to infrared,i.e., having a wavelength from 10 nm to 100,000 nm) when current flowsthrough the LED from the anode to the cathode.

As with the embodiments disclosed above using a semi-transparentconductive element 130A, 140A, embodiments using a plurality of positiveand negative transparent conducting layers 2130, 2140, can deposit aphosphor layer above the light emitting element 410, can deposit a lensabove the light emitting element 410, can include one or both of a heatsink and a heat spreading layer attached to the bottom of the firsttransparent substrate 950, and can replace the second transparentsubstrate 955 with a transparent conformal coat.

CONCLUSION

This disclosure is intended to explain how to fashion and use variousembodiments in accordance with the invention rather than to limit thetrue, intended, and fair scope and spirit thereof. The foregoingdescription is not intended to be exhaustive or to limit the inventionto the precise form disclosed. Modifications or variations are possiblein light of the above teachings. The embodiment(s) was chosen anddescribed to provide the best illustration of the principles of theinvention and its practical application, and to enable one of ordinaryskill in the art to utilize the invention in various embodiments andwith various modifications as are suited to the particular usecontemplated. All such modifications and variations are within the scopeof the invention as determined by the appended claims, as may be amendedduring the pendency of this application for patent, and all equivalentsthereof, when interpreted in accordance with the breadth to which theyare fairly, legally, and equitably entitled. The various circuitsdescribed above can be implemented in discrete circuits or integratedcircuits, as desired by implementation.

What is claimed is:
 1. A lighting element, comprising: a firstsubstrate; a first conductive element located on the first substrate; asecond conductive element located on the first substrate; alight-emitting element having a first contact and a second contact, thefirst and second contacts both being on a first surface of thelight-emitting element, the first contact being electrically connectedto the first conductive element, the second contact being electricallyconnected to the second conductive element, and the light-emittingelement being configured to emit light from a second surface oppositethe first surface with the light having a first narrow range ofwavelengths between 10 nm and 100,000 nm; a transparent layer locatedadjacent to the second surface of the light-emitting element; atransparent affixing layer located between the first substrate and thetransparent layer, the affixing layer being configured to affix thetransparent layer to the first transparent substrate; and a firsttransparent conductive layer formed at least partially adjacent to thefirst contact and at least partially adjacent to the first conductiveelement, the first transparent conductive layer configured toelectrically connect the first contact and the first conductive element,wherein the transparent layer and the transparent affixing layer areboth sufficiently transparent to visible light such that they will notdecrease light transmittance below 70%, the first and second conductiveelements are at least partially transparent to visible light, and thefirst transparent conductive layer is sufficiently transparent tovisible light such that it will not decrease light transmittance below70%.
 2. The lighting element of claim 1, further comprising: a secondtransparent conductive layer formed at least partially adjacent to thesecond contact and at least partially adjacent to the second conductiveelement, the second transparent conductive layer configured toelectrically connect the second contact and the second conductiveelement, wherein the second transparent conductive layer is sufficientlytransparent to visible light such that it will not decrease lighttransmittance below 70%.
 3. The lighting element of claim 2, wherein thelight-emitting element is configured to at least partially overlap atleast one of the first and second conductive elements.
 4. The lightingelement of claim 2, wherein the light-emitting element is configuredsuch that it does not overlap either of the first and second conductiveelements.
 5. The lighting element of claim 1, wherein the light-emittingelement is an ultrathin light-emitting element, having a thickness ofbetween 3 mil and 20 mil.
 6. The lighting element of claim 1, whereinthe transparent layer is one of a second substrate and a hardenedconformal coating.
 7. The lighting element of claim 1, wherein the firstand second conductive elements each comprise at least one of aconductive polymer strip, a nano-composite strip, a metal nanowire, acopper strip, an aluminum strip, a silver strip, and a strip containingan alloy of copper, aluminum, or silver.
 8. The lighting element ofclaim 1, wherein the first substrate is sufficiently transparent tovisible light such that it will not decrease light transmittance below70%.
 9. The lighting element of claim 1, wherein the first and secondconductive elements are both buss bars.